The dietary fibre is edible parts of plants' carbohydrates that are resistant to digestion in human small intestine. Diets naturally rich in dietary fibre support to prevent constipation, improve gastrointestinal health, glucose tolerance and the insulin response, and reduce the risk of colon cancer, hyperlipidemia, hypertension and other coronary heart disease risk factors. About 45% of the dietary fibre intake comes from grains and grain mixtures. In Latvia, there are neither data, nor investigations of the dietary fibre content in grain products during processing and in the end products in which manufacturers and consumers are interested. The aim of this paper was an approval of dietary fibre determination methodology by using analytical equipment the Full option science system (FOS) Analytical Fibertec E 1023. The dietary fibre determination experiments were carried out in the Research Laboratory of the Department of Food Technology at the Latvia University of Agriculture in 2009. The Total Dietary Fibre (TDF) content was analyzed in the samples of rye whole grain flour, rye whole grain bread, and wheat biscuit. Experiments showed that the fibre content in rye whole grain flour is 13.8 g 100 gE-1, in rye whole grain bread - 11.6 g 100 gE-1, and in the wheat biscuit - 1.9 g 100 gE-1. Reached data are comparable with results of other researchers' data.

Jerusalem artichoke powder (JAP) from Jerusalem artichoke (Helianthus tuberous L.) roots is a nutritive valuable product that can be used for a healthy product development. The influence of JAP on the quality and degree of liking of cakes was investigated. Sensory evaluation of cakes was realized in two stages: the first - to define the quality attributes of the cakes with JAP from the point of view of the experts, the second – to find out the consumers' views on the cakes, whose quality has been improved in accordance with the recommendations of the experts. As a control sample, the classic home cake was evaluated. Control sample was compared with the cakes, where the amount of wheat flour prescribed by recipe was partly substituted with JAP at different concentrations. Experts evaluated cakes and defined the highest acceptable concentrations of JAP in cakes. For the consumers it was offered to assess the cakes with JAP at concentration 30% and with different taste and aroma enhancers. Cakes with 30% of JAP additive were the most favoured by the sensory properties: aroma, texture, softness elasticity, porosity and softness, surface crust, appearance, colour, shape, and size. Results of analysis of variance showed that there no significant differences in the degree of liking between the cakes with JAP and the cakes with taste and aroma enhancer additives (p is greater than 0.05). There had been performed hardness analysis and colour measurement for cakes with JAP. The observed results declare high influence of aroma and taste enhancer on cakes structure and colour.